You probably don't remember who taught you how to wipe—your parents, most likely—or why you…
Read more Read more

To learn the best way, we asked the people who not only wash their hands the most, but desperately need to make sure they do a good job of it: Surgeons. One of our two surgeons washes his hands "at least 50 times a day," doing "not only a full scrub before each operation, but also before and after each patient [he sees] in the office and in the hospital."

How it's done now

Although I'm not, by any reasonable definition, extremely filthy, my parents have always nagged me to wash my hands better. Here's when and how I do it.

Wet hands with water

Put either bar soap or liquid soap on hands

Rub hands together like a villain

Intertwine fingers to get between fingers

Scrub the back of one hand with the other, then reciprocate

Rub hands together again

Rinse

I do this after I use the bathroom (even at home), when I'm preparing food, after I take out the trash, after I come home, before I eat and every time I "feel" my hands have gotten dirty. But is this right? Am I subjecting myself and all the people I touch to disgusting bacteria by not washing enough?

Why washing your hands is important

It was more than 150 years ago that Dr. Ignaz Semmelweis noticed that the patients in the care of nurses/midwives who washed their hands were three times less likely to die than the patients in the care of doctors, who didn't wash their hands at all. Even grosser (in retrospect), medical students didn't wash their hands between dissecting cadavers and caring for pregnant women, and managed to transmit puerperal fever as a result. Dr. Semmelweis instituted a rule to clean everyone's hands with a chlorine solution, which cut the death ratio to less than 1%.

Dr. Colin Knight explains:

Rather than being heralded as a hero for his observation, he was regarded as a nut and died in an insane asylum. It wasn't until Louis Pasteur showed the existence of germs in the 1860's did hand washing take off in medicine.

Dr. Isaac Yang points to studies to show that a lot of us—a disturbing amount—aren't even washing our hands at all, a century and a half after this discovery. Or, if we are, we're not doing it long enough. For example, in one study of college students' bathroom habits, 63% washed their hands, but only 38% used soap. Then, 32% used soap between 5 and 10 seconds, and a microscopic 2% used soap to wash for more than 10 seconds. When there wasn't someone watching students, that 63% dropped to 55%. That means 45% didn't wash their hands at all. College students are disgusting.

Unsurprisingly, guys are worse this whole "being clean" thing than girls, with only 48% of guys even washing at all, compared to 58% for the ladies.

So how should I do it?

The first step is just washing your hands, period. Use soap. If you spend 20-30 seconds washing your hands with soap, you're already going to be way ahead of most of the people out there in terms of cleanliness, no matter what your technique is.

Here's Dr. Knight's guide:

You can get your hands clean in less than 30 seconds. It is important to use clean, running water. After making a good lather with soap (any kind will do), scrub all over your hands making sure to get all around each finger and the backs of your hands. This scrubbing process should take 20 seconds, the amount of time it takes to get through the "Happy Birthday" song twice. After rinsing with clean, running water, you need to dry your hands with a clean towel. The legs of your jeans don't count, even if you put them on fresh this morning!

And Dr. Yang adds that there's a reason why surgeons on TV wash their hands with their hands up and elbows pointing down.

That is so the water drains from the fingertips and put all the debris and bacteria towards the elbows. So if you were to extrapolate that from surgeons to normal use, the most useful change you could make is rinsing your hands in the water with the fingertips pointed up towards the ceiling and wrists bent so that they are at the lowest point. This is so that your fingers are the cleanest and your wrists are the dirtiest, which makes sense.

And he also recommends you wash your wrists up to the forearm if you're doing something that really needs your hands to be clean, like when you're dressing a wound or making food.

And when should you wash your hands? The CDC says:

Before, during, and after preparing food

Before eating food

Before and after caring for someone who is sick

Before and after treating a cut or wound

After using the toilet

After changing diapers or cleaning up a child who has used the toilet

After blowing your nose, coughing, or sneezing

After touching an animal or animal waste

After touching garbage

You're probably doing all of these already, save for the animal and coughing/sneezing bits.

And if you really do want to wash like a boss (surgeon), imitate Dr. Yang. "We do it for 5 minutes, dividing each finger into 4-5 planes like a dice and washing each side of the dice with 20 scrubs."

You should also be careful if your skin has cracks or breaks in it. Dr. Knight explains:

If your hand have broken skin on them, it is hard to get them clean. When I was a primary care doctor in the Air Force, I saw a patient who had an infectious rash on his back. He noticed that he and his wife both got the same infection immediately following a massage by the base masseuse.

I decided to do a little detective work. I obtained a culture of his rash for reference and I had the public health officer bring the masseuse in for an examination. She had eczema with cracks in her skin between her fingers. I cultured those cracks and found that the exact same germ that was on her hands as the one that had caused my patient's infection. We arranged for the masseuse to be treated by a dermatologist and the germ went away. The moral of the story is that if you have breaks in your skin, be extra cautious about keeping your hands clean and consider seeking treatment.

What soap should I use?

Dr. Yang recommends liquid soap over bar soap, because the bar can collect bacteria and get dirty. Liquid dispensers have been shown recently to collect bacteria as well, so touchless motion-sensitive soap dispensers like this simplehuman one may be your best bet.

Any alternatives?

If you don't have time to wash your hands multiple times a day, or if you're not near a sink, Dr. Yang recommends alcohol washes.

The alcohol washes that are now available are 99% as effective as washing your hands. They take 5 seconds. You can also use them up your wrists and partial forearm. [They] have moisturizer plus alcohol hand washes all in one. I keep one handy on me at all times, because it is just better to use that at a restaurant than to go into the dirty environment of the restaurant restroom just to wash your hands.

Fortunately for folks like me who are cleaning their hands so many times a day, alcohol-based hand sanitizers (with at least 60% alcohol) are almost as effective as hand washing. Some of these have lotion in them, which may be helpful if you have sensitive skin, but I don't like the residue they leave behind. Alcohol sanitizers won't kill the spores of an infectious diarrhea called C. difficile and don't work if your hands are dirty.

The thing to remember is that washing your hands is both for killing bacteria and for removing dirt and debris, and these sanitizers only do one of these two things.

Acknowledgements and what I've learned

A sanitary air-five and a chest bump to our knowledgeable surgeons, who found free time between saving kids and cutting open brains to answer my questions. Thanks to them, my hands will be pristine whenever I need to make pasta, pick my nose, or perform intercourse on somebody.

Do it right is a section where we explore common activities that we all think we're doing correctly, but might not be. And if you know someone who insists that they're doing something right, feel free to pass this along to show them what the experts say. Do you want to know if you're doing something right? Email us at doitright@lifehacker.com and we'll find out.